It is interesting to look as artists past and present and to see the influences from earlier artists affecting the techniques and ideas of later artists. It is also illuminating to see how sculpture and canvas painting rub shoulders when thinking about artists who open up the painting's surface sometimes eliminating the canvas altogether to produce wall sculptures. For example Tatlin whose corner Reliefs used modern everyday materials to display sculptural works that were placed in the corner like Russian icons. Jean Arp also created wooden wall objects that might be regarded as sculptures, except that they maintain the traditional placement on walls.
Using shaped canvases Elizabeth Murray achieved a similar effect to Arp but her work is on shaped canvases.
It is also possible to think of Matisse's cut-outs as an "open" canvas. It isn't quite a collage but explores flat planes in similar ways to the work of Ben Nicholson. Picasso also used materials to open up the canvas, for example rope to form a sort of frame. He also made a guitar out of sheet metal which was wall mounted and virtually crosses the boundary, as the work of Arp and Tatlin did, between wall mounted object and/or sculpture.
Lucio Fontana slit or cut his canvases to create a fractured surface, literally opening the canvas. Max Ernst created a canvas, Two children threatened by a Nightingale, that opened in a different way, using a wooden gate to gain access to the canvas.
Francois Rouan stripped the canvas from its frame, cutting it into strips then wove it into a new image. Michele Whiting used a similar technique, but she used photographs instead of canvas.
Rauschenberg uses various materials to his canvas and sometimes takes us into the canvas with an object, for example his goat painting or the painting with the chair placed in front of the canvas which then becomes part of the painting.
Kenny Cole produces massed wall mounted boxes which open to reveal poetry and images, almost like opening a cupboard.
We then begin to move closer to installation which is the next stage in this artistic practice.